Dependencies say which task has to wait for which. In SimpleGantt you type them into a Predecessors column in your table, and the chart draws the arrows. Dependency arrows are a Pro feature (included in the trial).
The Predecessors column #
Each cell lists the tasks this row depends on. Separate several entries with a comma, a semicolon or a space.
| You type | Meaning |
|---|---|
| 3 | Starts after task 3 finishes (finish-to-start) |
| 3FS | Same as 3: finish-to-start |
| 3SS | Starts when task 3 starts (start-to-start) |
| 3FF | Finishes when task 3 finishes (finish-to-finish) |
| 3SF | Finishes when task 3 starts (start-to-finish) |
| 3FS+2d | Starts 2 days after task 3 finishes (lag) |
| 3FS-1d | Starts 1 day before task 3 finishes (lead) |
| 3SS+50% | Starts when task 3 is half way through |
| 3+1w, 3+4h | Lag in weeks or hours: d, w, h or %. A lag without a unit is in days. On a plan without times, an hour lag is rounded up to whole days and the Issues panel says so. |
| 2, 5SS+1d | Two predecessors |
| “Design review” | Refers to a task by name; quote names that contain spaces or separators |
What a reference points to #
SimpleGantt resolves each reference in this order:
- The value in your ID column, if you have one (1, 01 and 1.0 count as the same ID).
- Then the WBS number (1.2, 2.1.3), if you have a WBS column.
- Only when the table has neither an ID nor a WBS column: the row number within the data, counting the first task row as 1.
- Finally the task name, exact first, then ignoring upper and lower case.
An ID column is the safest choice: row numbers change when you sort or insert rows, IDs do not.
How it is drawn #
- Arrows run at right angles from the linked ends of the bars, and avoid crossing bars where possible.
- Point at an arrow to see which tasks it links and the link type. Critical links use the critical color when the critical path is on.
- Turn arrows on or off with Show dependency arrows under Edit > Schedule. In the free version, links are read (for the Issues panel) but no arrows are drawn.
The table decides the dates #
Dates you type are shown as typed, even when they contradict a dependency. When a task starts before its predecessor allows, the bar gets a dashed conflict outline, the grid row a warning icon, and the Issues panel lists it, so you can fix the date in the table. Highlight conflicts under Edit > Schedule turns the marker on or off. For tasks without a start date, SimpleGantt can compute one: see Calculate missing dates.
Problems SimpleGantt reports #
- A reference that matches no task, or a task that refers to itself.
- Two rows with the same ID (the first one is used).
- Circular dependencies. The Issues panel names the tasks in the loop, and those links are not drawn.
If a reference is not found, see A predecessor is not found.